Abstract: In order to improve the effective utilization of pesticide spraying, reduce pesticide residues and chemical pollution，a control system of target spraying robot in greenhouse was developed based on the host computer IPC and the lower computer PLC. This system has two operating modes, manual and automatic mode, which can control the mobile platform and manipulator, locate the plant diseases, open and close solenoid valve on each spray nozzle of the pole individually, implement target spraying on the cucumber leaves precisely in a square area of 0.2 m×0.2 m. Test results show that the system can work stably, and has relatively high positioning accuracy and availability.